The present invention relates to a method of casting metal products by transferring molten metal from a furnace into a casting cavity at a higher level by means of a pressurizing device capable of creating in the molten metal a pressure sufficient to lift it to said higher level. Similar methods have been disclosed in a number of publications, but none of them provides any practical guidance with regard to achieving a filling of the casting cavity as quickly as possible and at the same time avoiding undue turbulence and shock, such as when the surface of the molten metal hits the top wall of the casting cavity.
It is the object of the present invention to provide a method with which it is possible to fill the casting cavities concerned as quickly as possible whilst avoiding undue turbulence and shock. By, in this manner, controlling the action of the pressurizing device on the basis of one or more parameters relating to the flow of the molten metal into the casting cavity, it is possible to achieve a xe2x80x9cmould-filling profilexe2x80x9d, i.e. the level of molten metal in the mould as a function of time, corresponding to optimum filling conditions, e.g. first filling the major part of the casting cavity at a relatively high pressure, but not so high as to cause undue turbulence, and then reducing the pressure to achieve a gentle and shock-free filling of the top of the casting cavity.
The present invention also relates to an apparatus for carrying out the method according to the invention.
Advantageous embodiments of the method and the apparatus, as well as the effects thereofxe2x80x94beyond what is obviousxe2x80x94are explained in the following detailed part of the present description.